Learn Python by Building Data Science Applications

Refactoring the temperature conversion

In Chapter 2, First Steps in Coding – Variables and Data Types, we've performed a simple exercise by converting temperature from Fahrenheit to Celsius, and back. The approach was similar to how we'd use a calculator, except that we were able to store parameters beforehand, and then rerun the calculations for the new inputs. At this point, you can probably see that this is a great case for a separate function. So, let's refactor our code into a pair of functions:

def fahrenheit_to_celsius(temp):    CONST, RATIO = 32, 5/9    return (temp – CONST) * RATIOdef celsius_to_fahrenheit(temp):    CONST, RATIO = 32, 5/9    return (temp/RATIO) + CONST

Let's now test these function as follows:

>>> fahrenheit_to_celsius(100) ...